1. Field of the Invention
The present invention relates to a vehicle interior lamp that uses a semiconductor-type light source having light directionality as a light source. In particular, the present invention relates to a vehicle interior lamp that can efficiently discharge (release) heat generated from a light source.
2. Description of the Related Art
The above type of vehicle interior lamps has been conventionally known as exemplified by, for example, a vehicle interior lamp described in Japanese Patent Application Laid-Open No. 2002-331868. One of the conventional vehicle interior lamps is described below. A conventional vehicle interior lamp includes a light emitting diode (LED) arranged in a lamp chamber covered with a lamp cover which has a light-projection hole. Workings of the conventional vehicle interior lamp are as follows. When the LED lights up, the LED emits light which passes through the light-projection hole as spotlight and is projected onto a predetermined area within the interior of the vehicle. Semiconductor-type light sources such as LEDs consume low power and emit spotlight having light directionality, and therefore are suitable for the light source of the vehicle interior lamp.
The conventional vehicle interior lamps, however, do not take measures against heat generated from the LED. Therefore, there is a problem in the use of semiconductor-type light sources such as high-output LEDs in the conventional vehicle interior lamps.